PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “MANDIBULAR CONDYLE”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 325 records · Page 18Linked to original sources
PubMed1977

Mandibular condyle dislocation into the middle cranial fossa.

A case is reported of a woman aged 25 with a dislocation of the right mandibular condyle into the middle cranial fossa. The most striking clinical feature is a strongly limited mandibular movement and the fixation of the mandible in the dislocated position. Adequate radiographic examination including tomography is necessary to obtain the proper diagnosis and to determine the position of the condyle and the displaced bony fragments of the cranial base. Early diagnosis and treatment are very important for a successful reposition. In the described patient manual reposition of the dislocated condyle was obtained 2 days after trauma. The risk of intracranial complications makes close cooperation with a neurosurgeon necessary.

Adult↗
PubMed1997

The expanded mandibular condyle of the Megaladapidae.

The Megaladapidae have a posterior expansion of the articular surface of the mandibular condyle. Several other strepsirhine species exhibit a similar condylar surface. In this study, I propose two behavioral scenarios in which the posterior articular expansion might function: 1) contact with the postglenoid process and resistance to joint stress during browsing, and 2) movement against the postglenoid process during the fast closing and power strokes of mastication, as a consequence of large transverse jaw movements and associated with a strong mandibular symphysis. These models are evaluated through dissection of the TMJ in Lepilemur and from comparative anatomical observations on strepsirhines and ungulates. In Lepilemur the mandibular symphysis is unfused, but compared to the unfused symphyses of other strepsirhines is strengthened by interlocking bony projections (Beecher [1977] Am. J. Phys. Anthropol. 47:325-336). An accessory articular meniscus is found between the posterior articular expansion and the postglenoid process in Lepilemur, suggesting that significant movement occurs in this part of the TMJ. The symphysis is fused in adult specimens of Megaladapis. A posterior articular expansion is common among ungulates, and its presence is associated not with browsing but with symphyseal fusion. This supports the second model and suggests that the posterior articular expansion functions as a movement surface during mastication. Schwartz and Tattersall ([1987] J. Hum. Evol. 16:23-40) cite the posterior articular expansion as a synapomorphy uniting an Adapis-Leptadapis clade with a Megaladapidae-Daubentonia-Indridae clade. The comparative evidence suggests that the posterior articular expansion has evolved convergently in adapines, notharctines, megaladapids, hapalemurids, and indrids as part of a functional complex related to herbivory. However, close morphological similarity of the posterior articular expansion among genera within these strepsirhine subfamilies and families indicates that it is probably a reliable synapomorphy at lower taxonomic levels.

Animals↗
PubMed2001

[X-ray and clinical characteristics in sagittal fracture of the mandibular condyle].

OBJECTIVE: To study the X-ray and clinical characteristics in sagittal fracture of the mandibular condyle (SFMC). METHODS: 14 cases (15 sides) of SFMC in 48 cases who had condylar fractures were studied in the research, every patient was examined by the conventional x-ray, 2D-CT and 3D-CT, and followed up for 3-39 months. RESULTS: The fracture line mainly passed through lateral 1/3 and middle 1/3 of anterior condyle and the middle 1/3 of posterior condyle. Following-up (3-39 months) showed that the patients' occlusions were normal in all cases. CONCLUSIONS: The fracture line mainly located in the lateral pterygoid muscle fossa. Good results can be gotten by effective treatment. The 2D-CT and 3D-CT are valuable to the diagnosis.

Adolescent↗
PubMed2004

Mandibular condyle fractures: determinants of treatment and outcome.

PURPOSE: The objective of this study was to analyze the principal variables that determine the choice of the method of treatment and the outcome in condylar fractures. MATERIALS AND METHODS: We conducted a retrospective analysis of 104 mandibular condyle fractures to analyze and determine the relation between the principal clinical variables and the postoperative results. All patients underwent a clinic-radiologic investigation focusing on fracture remodeling, evolution, dental occlusion, and symmetry of the mandible. We analyzed the influence of the preoperative clinical variables (level of fracture, treatment, postoperative physical therapy, displacement and dislocation, comminution, loss of ramus height, patient age, gender, etiology, occlusion, status of dentition, and presence of facial and mandibular fractures) over the postoperative results and outcome. RESULTS: The principal factors that determined the treatment decision were the level of the fracture and the degree of displacement. The level of the fracture influenced the degree of preoperative coronal and sagittal displacement (neck fractures had greater medial and anterior displacement than head and subcondylar fractures) and the treatment applied. The functional improvement obtained by open methods was greater than that obtained by closed treatment. Open treatment increased the incidence of postoperative condylar deformities and mandibular asymmetry. CONCLUSION: The variables that influenced the method of treatment and predicted the prognosis are the level of fracture, degree and direction of displacement of the fractured segments, age, medical status of the patient, concomitant injuries, and status of dentition.

Adolescent↗
PubMed2001

Osteoid osteoma in mandibular condyle.

A 21-year-old Japanese woman presented with trismus and spontaneous pain (especially at night) around the left temporomandibular joint. Radiographic examination showed a subcortical sclerosed nodule measuring approximately 8 mm in diameter on the infero-lateral aspect of the left mandibular condyle. Amputation of the condyle was performed under general anesthesia. The patient has been in good condition 8 years postoperatively. The histopathology of the specimen consisted of actively proliferating osteoblasts mixed with an interlacing network of woven bone and osteoid trabeculae. Histopathological diagnosis was osteoid osteoma.

Adult↗
PubMed2005

Mechanical strain induces Cbfa1 and type X collagen expression in mandibular condyle.

Core binding factor a1 (Cbfa1) is a crucial transcriptional factor for chondrocyte maturation and osteoblast differentiation in the mandibular condyle. To quantitatively assess the amount of mRNA expression of Cbfa1 and type X collagen in response to mandibular advancement. 420, 35-day-old female Sprague-Dawley rats, were randomly divided into 20 experimental and 10 control groups corresponding to 10 time points. Experimental animals were advanced in either single or stepwise manner. Condylar cartilage was dissected under microscope and total RNA was extracted, Cbfa1 and type X collagen mRNA was quantified with real-time RT-PCR. Cbfa1 and type X collagen mRNA expression for all groups reached their peak on experimental day 21. During single advancement, Cbfa1 and type X collagen mRNA expression was consistently higher (3-fold and 2.8-fold respectively) than that of stepwise advancement (2-fold). The second advancement in the stepwise group resulted in both Cbfa1 and type X collagen level reaching another peak on day 51. Mandibular advancement promoted chondrocytes maturation and osteoblast differentiation by upregulating Cbfa1 expression. Stepwise advancement produced a higher level of Cbfa1 and type X collagen expression leading to bigger cartilage template onto which bone will form through endochondral ossification.

Animals↗
PubMed2002

Regeneration of the mandibular condyle after unilateral condylectomy and myotomy of the masseter in lambs.

We investigated the degree of regeneration of the mandibular condyle after unilateral condylectomy and myotomy of the masseter in growing lambs. Four 10-week-old lambs had unilateral condylectomy and myotomy of the superficial layer of the masseter on the right side, and were killed 3 months later. The joints were examined radiologically and histologically. All joints showed poor regeneration of the condylar head. In the medial plane there was partial condylar and articular cartilage reformation, but in the lateral plane there was neither condylar nor cartilaginous reformation. The articular cartilage of the temporal bone was thicker in the medial plane and the disc was thicker in the central plane, than in unoperated joints. We conclude that unilateral condylectomy and myotomy of the masseter in the growing period results in poor regeneration of the condyle.

Animals↗
PubMed2003

Bone marrow edema of the mandibular condyle related to internal derangement, osteoarthrosis, and joint effusion.

PURPOSE: The purpose of this prospective study was to evaluate whether common magnetic resonance imaging (MRI) variables such as temporomandibular joint (TMJ) internal derangement, osteoarthrosis, and effusion may predict the diagnostic group of bone marrow edema of the mandibular condyle. MATERIALS AND METHODS: The relationship between bone marrow edema and TMJ disc displacement, osteoarthrosis, and effusion was analyzed in MRIs of 120 TMJs in 73 consecutive patients with TMJ pain and/or a clinical diagnosis of TMJ internal derangement type III (disc displacement without reduction). The diagnostic bone marrow edema group was comprised of 54 TMJs in 40 patients with a unilateral or bilateral MRI diagnosis of bone marrow edema. The control group consisted of 66 non-bone marrow edema TMJs in 33 patients with a bilateral MRI finding of an absence of bone marrow edema. A logistic regression analysis was used to compute the odds ratios for internal derangement, osteoarthrosis, and effusion for non-bone marrow edema TMJs (n = 66) versus TMJs with bone marrow edema (n = 54). RESULTS: Using Chi;(2) analysis for pair-wise comparison, the TMJ-related data showed a significant relationship between the MR imaging findings of TMJ bone marrow edema and those of internal derangement (P = .000), osteoarthrosis (P = .000), and effusion (P = .010). Of the MRI variables considered simultaneously in the multiple logistic regression analysis, osteoarthrosis (P = .107) and effusion (P = .102) dropped out as nonsignificant in the diagnostic bone marrow edema group when compared with the control group. The odds ratio for individuals with an internal derangement showing bone marrow edema was strong (3.6:1) and highly significant (P = .000). Significant increases in risk of bone marrow edema occurred with disc displacement without reduction and osteoarthrosis (9.2:1) (P = .000) and disc displacement without reduction and effusion (6.4:1) (P = .002). CONCLUSIONS: The results suggest that the MR imaging findings for TMJ bone marrow edema are related to those of internal derangement, osteoarthrosis, and effusion. However, the data re-emphasize the aspect that internal derangement, osteoarthrosis, and effusion may not be regarded as the unique and dominant factors in defining TMJ bone marrow edema instances.

Adolescent↗
PubMed2000

Effect of intermittent administration of human parathyroid hormone (1-34) on the mandibular condyle of ovariectomized rats.

Intermittent administration of human parathyroid hormone (1-34) (PTH) increases bone mass in lumbar vertebrae and long bones of osteoporotic experimental animals. However, whether PTH has the same effect on jaw bones remains unclear. This study determined the effect of intermittent administration of PTH on rat mandibular condyle affected by estrogen deficiency. Fifty 6-month-old rats were either sham operated or ovariectomized, then divided into five groups depending on surgical procedure and hormone administration: sham + vehicle (SV), OVX + vehicle (OV), OVX + PTH 6 micrograms/kg once per week (OP6-1), OVX + PTH 60 micrograms/kg once per week (OP60-1), and OVX + PTH 20 micrograms/kg three times per week (OP20-3). PTH or vehicle was injected intermittently for 6 months in 5 rats of each group either immediately after surgery in a preventive administration experiment, or injected starting 6 months after surgery in a therapeutic administration experiment. The mandibles were excised, and bone morphometry was performed using confocal laser scanning microscopy and soft X-ray images. In both experiments, the bone volume of the OV groups was significantly lower than that of the SV group (P < 0.01); also, depending on dose and frequency, the bone volume of the OP group was higher than that of the OV group, particularly in the OP20-3 group. The value of mineralized surface of the OP groups was significantly higher than that of the OV group (P < 0.01), whereas the value of eroded surface of the OP groups was not significantly higher than that of the OV group. This study indicates that preventive and therapeutic intermittent administration of PTH in ovariectomized rats increase the bone formation in rat mandibular condyle without accelerating bone resorptive activity. This anabolic effect was best induced by the injection mode of 20 micrograms/kg three times per week.

Animals↗
PubMed2000

The association of temporomandibular joint pain with abnormal bone marrow in the mandibular condyle.

PURPOSE: This study investigated the association between temporomandibular joint pain and bone marrow alterations in the mandibular condyle seen on magnetic resonance (MR) images. PATIENTS AND METHODS: The study was based on 112 temporomandibular joints in 112 patients with disc displacement without reduction. Thirty-four patients with abnormal bone marrow on MR images were compared with a control group of 78 patients with normal bone marrow. The analysis was based on proton density and T2-weighted MR images in the oblique sagittal and coronal planes. The degree of pain was correlated to the status of the bone marrow using statistical methods. RESULTS: The degree of pain in joints with abnormal bone marrow was higher than in joints with normal bone marrow signal on MR images (P = .0045). CONCLUSION: Because the stage of internal derangement was similar in both groups, more intensive pain appears to be associated with bone marrow alterations.

Adolescent↗
PubMed1987

Biological reconstruction of the mandibular condyle.

It is proposed in the scientific literature that the costochondral graft is the most suitable method for reconstruction of the mandibular condyle. Success is demonstrated by function and continued growth. Creeping substitution of osteoid does not compromise the osteochondral graft. In many species cartilage autografts survive and grow despite the absence of perichondrium and synovial membrane. These studies emphasise the importance of transferring only a thin cartilage cap on an osteochondral graft for optimum survival of cartilage cells. Many experiments involving metatarsals or ephiphyseal heads have failed to reproduce the cartilaginous cap found in the normal condyle. Despite evidence from animal studies, there is human experience of the unpredictability of costochondral grafts. Much remains to be evaluated, in animal model systems comparable with man, before optimum joint replacement can be assured in the treatment of those with congenital and acquired deformities of the condyle.

Animals↗
PubMed1978

Central giant-cell lesion in the mandibular condyle. Report of a case.

Giant-cell lesions of the temporomandibular joint are rare. In the present case a central giant-cell lesion of the temporomandibular joint is described, and the distinction between central giant-cell reparative granulomas and giant-cell tumors is discussed. Successful reconstruction of the temporomandibular joint by means of an 8 cm. costochondral graft in an elderly patient with a central giant-cell lesion of the mandibular condyle is also reported.

Giant Cell Tumors↗
PubMed2002

Computer-assisted orthognathic surgery: clinical evaluation of a mandibular condyle repositioning system.

PURPOSE: The purpose of this study was to evaluate a new method for positioning the mandibular condyle during orthognathic surgery based on 3-dimensional optical localization of infrared emitting diodes. PATIENTS AND METHODS: Eleven patients ("empirical group") underwent condylar repositioning using the empirical repositioning method (standard technique) and were considered controls. In 10 patients ("active group"), the computer-assisted system was used to replace the condyle-bearing fragment in its sagittal preoperative position. In these patients, the condylar torque was not controlled. In the third group of 10 patients ("graft group"), the computer-assisted system was used to replace the condyle in all 3 directions. Very often it was necessary in this group to fill the osteotomy gap with a bone graft. The clinical evaluation was based on 4 major criteria: the quality of the postoperative occlusion, the stability of skeletal position on successive cephalometric radiographs, the occurrence of temporomandibular dysfunction (TMD), and the preservation of mandibular motion. Clinical assessment was made at 1, 3, 6, and 12 months follow-up. RESULTS: Forty-five percent of the "empirical group" did not have the expected postoperative occlusion, 5 patients showed evidence of clinical relapse at 1 year, 45% had worsened TMD status, and only 63.37% of mandibular motion had been recovered at 6 months. All the patients in the "active group" had the expected occlusion and only 1 patient exhibited a mild relapse and TMD symptoms; however the average mandibular motion recovery was only 62.65% at 6 months. All the patients in the "graft group" had a good occlusion and no relapse or TMD. Their percentage of mandibular motion recovery was 77.58%. CONCLUSION: The quality of sagittal repositioning is the main factor contributing to a good occlusion and bone stability. Functional results (in particular, recovery of mandibular motion) are more related to limiting condylar torque.

Adolescent↗